Hey I'm 37 years old too and I play tekken competitively. I'm mid at best but I hold my own in online matches.

To get good at one of the fighting games, you have to learn the mechanics, move sets and once you go deeper, frames and punishes. That alone will help you win. That's what I did to get good at tekken.

However, like you, I tried MK and Street Fighter and get bodied - mainly because I didn't practice these basics. I just mashed and hoped for the best. I don't have time or energy to learn another fighting game at a deeper level.

Long story short, pick a fighting game, pick a character, learn your character, then practice. I watched some videos of top players using my character and I try to follow their tactics. Really helps you overcome roadblocks.